* Sarksyan had big lead in polls before vote
* Incumbent had promised stability
* Campaign tainted by assassination attempt on rival (Updates with exit poll)
By Hasmik Mkrtchyan
YEREVAN, Feb 18 (Reuters) - Armenian President Serzh Sarksyan will secure a new five-year term in a election on Monday, an exit poll showed after a vote overshadowed by a lack of serious opposition and an attempt to kill a minor candidate.
The exit poll by Baltic Surveys/The Gallup Organization, reported by Armenian television, put Sarksyan on 58 percent of votes cast. His nearest rival, U.S.-born Raffi Hovannisian, trailed on 32 percent.
Sarksyan, 58, has vowed to sustain economic recovery in his landlocked South Caucasus country and said before the vote he would ensure stability after years of war and upheaval.
The continued peace of a region where pipelines take Caspian oil and natural gas to Europe is a concern for foreign investors and neighbours, especially as relations are fraught with fellow former Soviet republic Azerbaijan.
“I voted for the future of Armenia, for the security of Armenia, for the security of our citizens,” Sarksyan said as he cast his vote at a polling station in the capital, Yerevan.
The exit poll was carried out among 19,130 voters at 122 polling stations.
Sarksyan will also hope the election secures the approval of international observers.
The last presidential election, in 2008, was marred by clashes in which 10 people were killed, but there were no immediate reports of violence on Monday.
Sarksyan’s message has resonated with many voters in the country of 3.2 million, where more than 30 percent of the population live below the poverty line, the average monthly salary is about $300 and unemployment was 16 percent in 2012.
“Sarksyan promotes the improvement of an educated society, which is a guarantee of Armenia’s future,” said Artak Avetsyan, 31, a teacher who came to cast his ballot for the incumbent.
But with none of Sarksyan’s serious opposition rivals choosing to stand, election observers expressed concerns over the democratic credentials of the vote.
Officials from the Parliamentary Assembly of the Council of Europe (PACE) reported apathy and lack of confidence in the electoral process among the public when they visited the country in January.
Questions also linger over security in a nation locked in a dispute with it neighbour Azerbaijan over Nagorno-Karabakh, an ethnic Armenian-majority enclave inside Azerbaijan over which Armenians and Azeris fought a war in the 1990s. Sarksyan, like many of his generation, is a veteran of that war.
Sarksyan has accused Azerbaijan of threatening a new war. Baku denies it is the aggressor in the conflict and says Armenia should hand back control of Nagorno-Karabakh.
Security concerns were underlined by an attack on one of the candidates, Paruyr Hayrikyan, 63, an outsider in the election who was shot in the shoulder on Jan. 31.
Another dark horse in the race, Andrias Ghukasyan, went on hunger strike at the start of the campaign to press for Sarksyan’s candidacy to be annulled and for international observers to boycott the vote.
A third candidate, Arman Melikyan, had said he would not vote because he believes the election would be skewed in Sarksyan’s favour. Other potential rivals said they chose not to take part in the race for similar reasons.
Results are expected to be clear within 24 hours. (Additional reporting by Thomas Grove, Writing by Timothy Heritage; Editing by Jason Webb)